Ignition distributor



W. E. scHwARzMANN ETAL 2,441,922

' IGNITION DISTRIBUTOR Filed Nov. 20, 1945 z Sheets-Sheet 1 ATTOHNEY y 1948. W. E. SCHWARZMANN HAL 294413922 IGNITION DISTRIBUTOR Filed Nov. 20, 1943 2 Sheets-Sheet 2 ATTORNEY Patented May 18, 1948 UNITED.- STATES' PATENT OFFICE.

IGNITION DISTRIBUTOR Wolfgang E. Schwanmann, Longmeadow, and Edward M. Bach, Agawam, Mesa, assignors to American Bosch Corporation, Springfield, Mass., a corporation of New York Application November 20, 1943, Serial No. 511,002

12 Claims. 171-209) 1 a This invention relates to distributors for ignition generators (including magnetos and timerdistributors of battery ignition systems) and it relates particularly to distributors incorporated in multicoil gearless type of multicylinder generators in which the ignition impulses are distributed from a plurality of ignition coils t0 sparkplugs in the cylinders of the multicylinder internal combustion engine driving the generator at the cam shaft speed of the engine, and in which no speed change gearing exists between the distributor rotor and circuit breaker mechanism, or between the distributor rotor and generator rotor in the case of a magneto. Such generators may be low tension or high tension, and may be associated with gas engines, semi-Diesel or other types of internal combustion engines which have any suitable number of cylinders in any suitable arrangement operatingon any suitable cycle as the two or four stroke cycle, and which have any suitable number of sparkplugs per cylinder in any suitable arrangement of sets of the sparkplugs.

In prior generators of this kind, separate and continuous distributor rotor rings have been provided for each ignition coil, and these rings and their distributing electrodes were arranged axially along the shaft inside distributor blocks in the form of one or two superposed rings having circularly-arranged stationary sparkplug terminals cooperative in sets with respective ones of said electrodes. Such generators, in the form of twocoil, or so-called double, magnetos are shown in U. S. Patents Nos. 2,116,353 and 2,312,447. Besides always requiring two kinds of conductor elements between the high tension terminals of the coils and the distributor rings, they sometimes required, for the same factor of-safety against electrical flashover in or from the distributor mechanism, increased height and weight of shaft and frame on account of the superposed arrangement of the distributor rotor rings.

The primary object of this invention is to simplify the distributor mechanism of this type of generator, and to reduce the dimensionsthereof particularly its height and/or to improve its mechanical and electrical reliability over long periods in the severe service to which it may be subjected as on airplanes operating under various conditions of temperature and atmospheric density at various altitudes and latitudes. We accomplish this by replacing the distributor rings with ring segments angularl offset and insulated respective coils to the segments. In some cases we prefer to arrange the distributing electrodes in the one horizontal plane to further decrease the required height and weight of the generator and to improve its durability in sereve service, and mother cases prefer to arrange those electrodesin diflerent planes to increase the flashover distance between the sparkplug terminals of the stationary distributor block and to ground.

Other objects and advantages will appear from the following description of an exemplary ignition generator in the form of a high tension double magneto adapted to be driven at the cam shaft speed by a 4-stroke cycle internal combustion engine with two sparkplugs per cylinder, and having the sparkplug terminals of the distributor block arranged in two horizontal planes for the respective sparkplugs of all the engine cylinders, to cooperate with the axially offset distributing electrodes. In the accompanying drawings of this embodiment of the invention.

Fig. 1 is a central vertical section, partly in elevation and partly broken away, of the magneto which illustrates both a fourand a six-cylinder type; Figs. 2, 2A, 2B and 20 show the relative positions of the ring segments, distributing electrodes and sparkplug terminals of the distributor mechanism at the successive periods of ignition of the magneto as a four-cylinder type; and Figs.

3, 3A, 3B, 3C, 3D and 3E show the relative positions thereof at the successive periods of ignition of the magneto as asix-cylinder type.

Referring to Fig. 1, the magneto frame-has a mounting flange I, lower and upper sections 2 and 3 and a circuit breaker cover 4, of cast aluminum alloy, fastened toegther to forma rigid housing. The vertical shaft 5 is journaled in a bearing in flange I, and also in disc 6 which is secured as at I to the ring flange 8 and-which carries the circuit breaker mechanism including the pairs of contacts 9 and ill in cooperation with the lobed cam ll fastened on the shaft 5. The shaft 5 also has fastened to it the generator or magnetic rotor l2 of sheet steel with radial poles of the well known number and arrangement for a four or six-cylinder magneto as the case may be. Also fastened to the shaft 5 is the distributor rotor 13 and the gear I4 adapted to be driven by the internal combustion engine associated with the magneto at cam shaft speed of the engine, Cooperative with the generator rotor I2 is a laminated magnetic structure l5 forming a stator of from each other, and arranged in one horizontal 'well known kind including two magnets and two high tension ignition coils I6 and I1, the primary terminalsof the coils being electrically connected 3 by wires l8 and I8 to the respective pairs of breakercontacts 9 and I0, and the secondary terminals of the coils being electrically connected to respective insulated and shrouded conductors 20 and 2|.

The distributor rotor |3 carries two ring segments 22 and 23 insulated from each other and lying in one horizontal plane so as to reduce the height and weight of the rotor and therefore of the shaft and frame section 3, and also to give increased stability, rigidity and endurance to the magneto in service particularly under severe vibration on airplane. The strip insert 24 electrically connects the segment 22 to the distributing electrode 25, and the strip insert 26, insulated from the insert 24, electrically connects the segment 23 to the distributing electrode 21. As shown, these electrodes 25 and 21 are angularly offset from each other, and also they lie in different horizontal planes so as to increase the fiashover distance between sparkplug terminals in the stationary distributor block 28 hereinafter described. However, if desired to further decrease the height and weight of the rotor l3 and of the distributor block 28 as well as of shaft 5 and frame section 3, these electrodes may under certain conditions of operation be positioned in the same horizontal plane. Also, if desired, an insulating washer 29 may .be located over rotor I3 and block 28 to further reduce likelihood of electrical fiashover from these to ground.

The stationary distributor block 23, suitably fastened to stator I5, has one complete circle of sparkplug terminals 30 in cooperation with electrode 25 and another complete circle of sparkplug terminals 3| arranged in another horizontal plane in cooperation with electrode 21, there being four terminals in each circle for a fourcylinder magneto and six for a six-cylinder magneto. It will be understood, however, that if the electrodes 25 and 21 are arranged in the same horizontal plane, as aforesaid, all the terminals 33 and 3| will be arranged in a single circle, and thereby decrease the height and weight of the distributor block 28 also. Furtherm'ore, if desired, brushes with sliding contacts may replace either or both of the jump spark connections between the conductors 20, 2| and segments 22, 23, and/or either or both of the jump spark connections between electrodes 25, 21 and terminals 30, 3|. In any event, the terminals 30 and 3| are provided with piercing screws 32 for connection to respective cables which are intended to be inserted in the holes 33 from the outside periphery of the block l3 and to be led through the ignition manifold 34 of the shielding harness to respective sparkplugs in the engine cylinders in the order hereinafter described.

Referring now to Figs. Z-ZC, the positions of the ring segments 22 and 23 relatively to the conductors and 2|, and the simultaneous positions of the distributing electrodes and 21 relatively to the sparkplug terminals and 3|, are illustrated for the successive periods of ignition in each rotation of the magneto in the direction of the arrows. In Fig. 2 the high tension terminal of coil |6 is electrically connected by conductor 20, ring segment 22 and distributing electrode 25 to that terminal 30 which is electrically connected to that sparkplug designated IL as the left hand one of the two sparkplugs is cylinder No. 1. At the same period of ignition the high tension terminal of coil [1 is electrically connected by conductor 2|, ring segment 23 and distributing electrode 21 to that terminal 3| which is connected to that sparkplug designated IR as the right hand one in the same cylinder. In Fig. 2A, after 90 rotation from Fig. 2 in the direction of the arrow, coil I8 is electrically connected, through the same segment 22 and the electrode 25 as beiore,to sparkplug terminal 30 connected to that sparkplug designated 2L as the left hand one of the two sparkplugs in cylinder No. 2, while coil I1 is connected, through the same segment 23 and its electrode 21, to sparkplug terminal 3| connected to that sparkplug designated 2R as the right hand one in cylinder No. 2. In Fig. 2B, coil I6 is connected, through segment 23 and electrode 21, to that terminal 3| which is connected to that sparkplug designated 3L as the left hand one of the two sparkplugs in cylinder No. 3, while coil I1 is connected, through segment 22 and its electrode 25, to that terminal 30 which is connected to that sparkplu designated 3R as the right hand one in cylinder No. 3. In Fig. 2C coil I6 is connected, through segment 23 and electrode 21, to that terminal 3| which is connected to that sparkplug designated 4L as the left hand one of the two sparkplugs in cylinder No. 4, and coil I1 is connected, through segment 22 and electrode 25, to that terminal 30 which is connected to that sparkplug designated 4R as the right hand one in cylinder No. 4.

Figs. 3-3151 illustrate the relative arrangement of the conductors 20, 2|, the segments 22, 23 with their respective electrodes 25, 21 and the sparkplug terminals 30, 3| at successive periods of ignition in one rotation of the magneto of Fig. 1 considered as a fi-cylinder magneto rotating in the direction of the arrows. As in the case of the 4-cylinder magneto of Figs. 2-2C, the coil I6 is connected to one set of sparkplug terminals connected to those sparkplugs designated as IL- BL, whereas the other coil 11 is connected to the other set of sparkplug terminals connected to those sparkplugs designated as lit-6R, the nomenclature corresponding to the foregoing. It will be observed that segment 22 with its electrode 25 connects coil Hi to terminals 30 in Figs. 3, 3A and 3B and connects coil H to the remaining terminals 30 in Figs. 30', 3D and 3E, while the other segment 23 with its distributing electrode 21 connects coil H to terminals 3| in Figs. 3, 3A and 3B and to the remaining terminals 3| in Figs. 30, 3D and 3E.

It will be observed in both the i-cylinder magneto of Figs, 2-2C and the G-cylinder magneto of Figs. 3-3E, that at every period of ignition the coil I6 is connected to one set of sparkplug terminals which are connected to sparkplugs designated herein as L, whereas the other coil I1 is connected to the other set of sparkplug terminals which are connected to sparkplugs designated herein as R, those sparkplugs of each set being supplied successively in the order of the numbers 1-4 or 1-6 preceding the letter L or R and the sequence being repeated in each rotation of the magneto. Also it will be observed that in each rotation each distributing electrode first connects with half the number of terminals of one set, L or R as the case may be, and then with half the number of terminals of the other set. There is an electrical advantage found in the operation of the magneto under some conditions by having the same coil always supply the same set of sparkplugs, and there is some structural advantage in some embodiments, and some fiashover advantages in the operation of the magneto, by having each distributing electrode I connect to sparkplug terminals of both sets in each rotation of the magneto.

As aforesaid. the dimensions of the magneto, particularly its height, are decreased by arranging the ring segments 22, 23 in one horizontal plane, and further by arranging the distributing electrodes 25, 21 in one horizontal plane. Furthermore. in the first case, the conductors 20, M from the coils to the ring segments are identical and the distributing rotor is reduced in height and weight; and in the second case the distributing rotor is further reduced in height and weight and the distributor block is reduced in height and weight. Also, these arrangements result in reductions of the length and weight of shaft 5 and the height and weight of the frame section 3, and therefore in the height and weight of the magneto. In such cases, however, the flashover or leakage distance in the distributor mechanism may be reduced. Therefore, the arrangement to be adopted in every given case is influenced by considerations in manufacture and operation, including the materials to be used, the temperature and humidity to be expected in operation, and the altitude at which the magneto is to be operated without supercharging. Obviously, as the length of the shaft 5 is reduced. the magneto, besides being lighter, lower and more compact, becomes more durable in operation particularly when subjected to severe vibration as on airplanes.

It is apparent that this distributor mechanism may be used in magnetos, or in the timer-distributors of battery ignition systems, having the plurality of coils associated with the generator by being incorporated or mounted separately therefrom. It is also apparent that this distributor mechanism may be used in low tension generators, instead of high tension generators as herein shown, in which event, however, it is generally preferable to use brushes in the electrical circuit of the distributing rotor instead of the jump spark connections herein shown.

Many changes and modifications may be made in the preferred embodiment of the invention herein described. For example, the generator may have any suitable plurality of ignition coils incorporated in or associated with it instead of the two coils herein illustrated, provided that there is provided a like plurality of ring segments with respective distributing electrodes. Also the generator may be arranged for any suitable number of sparkplug terminals other than the 4 or 6 herein shown in each set thereof, and with other suitable arrangements of electrical connections from the sparkplug terminals to the sparkplugs in the engine cylinders. Also the magneto herein illustrated may be of any suitable type, such as one having a magnet rotor instead of that herein shown, or one having other suitable arrangements of ignition coils and magnetic stators. Also the circuit breaker mechanism may be of any suitable type and electrically connected to the coils in any suitable way. These and other changes and modifications are intended to be covered by the broad terms of the appended claims.

Having thus described our inventon, what we claim is:

1. In multicylinder ignition generators of the multicoil gearless type; a shaft adapted to be driven by an internal combustion engine at the cam shaft speed thereof; aplurality of generating coils associated with the generator; circuit breaker mechanism electrically connected to the coils and having an element fast with the shaft;

6 and distributor mechanism which includes a rotor fast with the shaft and having in one plane a like plurality or ring conducing segments extending around a substantial portion of said rotor and angularly offset and insulated from each other and rotatable upon rotation of said rotor, means for electrically connecting the said segments to respective coils at the periods of ignition of the generator, said rotor also having a like plurality of distributing electrodes angularly offset from each other and in different planes and electrically connected to respective segments, and said mechanism also including a stationary distributor block surrounding said rotor and having sparkplug terminals cooperative selectively with electrodes at said periods of ignition.

2. In multicylinder ignition generators of the multicoil gearless type; a shaft adapted to be driven by an internal combustion engine at the cam shaft speed thereof; a plurality of generating coils associated with the generator; circuit breaker mechanism electrically connected to the coils and having an element fast with the shaft; and distributor mechanism which includes a rotor fast with the shaft and having in one plane a like plurality of ring conducting segments extending around a substantial portion of said rotor and angularly offset and insulated from each other and rotatable upon rotation of said rotor, means for electrically connecting each segment to all the coils at the periods of ignition of the generator during each rotation of the shaft, said rotor also having a like plurality of distributing electrodes angularly offset from each other and in different planes and electrically connected to the segments respectively, said mechanism including a stationary distributor block surrounding said rotor and having sparkplug terminals cooperative selectively with electrodes at said periods of ignition.

3. In multicylinder ignition generators of the multicoll gearless type; a shaft adapted to be driven by an internal combustion engine at the cam shaft speed thereof; a plurality of generating coils associated with the generator; circuit breaker mechanism electrically connected to the coils and having an element fast with the shaft; and distributor mechanism which includes a rotor fast with the shaft and having in one plane a like plurality of ring conducting segments extending around a substantial portion of said rotor and angularly offset and insulated from each other and rotatable upon rotation of the rotor, means for electrically connecting the said segments to respective coils at the periods of ignition of the generator, said rotor also having a like plurality of distributing electrodes angularly offset'from each other and in different planes and electrically connected to the segments respectively, said mechanism including a stationary distributor block surrounding said rotor and having sparkplug terminals cooperative with the electrodes and arranged in sets; the electrodes and terminals being positioned relative to each other so that at each of said periods of ignition the coils are electrically connected through respective electrodes to selected terminals of different sets thereof.

4. In multicylinder ignition generators of the multicoil gearless type; a shaft adapted to be driven by an internal combustion engine at the cam shaft speed thereof;' a plurality of generating coils associated with the generator; circuit breaker mechanism electrically connected to the coils and having an element fast with the shaft; and distributor mechanism which includes a rotor fast with the shaft and having in one plane a like plurality of ring conducting segments extending around a substantial portion of said rotor and angularly offset and insulated from each other with the segments being rotatable upon rotation of the rotor, means for electrically connecting said segments to respective coils at the periods of ignition of the generator and also having a like plurality of distributing electrodes angularly offset from each other and in different planes and electrically connected to the segments respectively, said mechanism including a stationary distributor block surrounding said rotor and having sparkplug terminals cooperative with the electrodes and arranged in sets; the electrodes and terminals being positioned relative to each other so that at all the successive periods of ignition of the generator in each rotation of the shaft each coil is selectively connected electrically to all the terminals of a respective set thereof.

5. In multicylinder ignition generators of the multicoil gearless type; a shaft adapted to be driven by an internal combustion engine at the cam shaft speed thereof; a plurality of generating coils associated with the generator; circuit breaker mechanism electrically connected to the coils and having an element fast with the shaft; and distributor mechanism which includes a rotor fast with the shaft and having in one plane a like plurality of ring conducting segments extending around a substantial portion of said rotor and angularly offset and insulated from each other and rotatable upon rotation of said rotor with the segments being electrically connected to the respective coils at the periods of ignition of the generator and also having a like plurality of distributing electrodes angularly offset from each other and in different planes and electrically connected to the segments respectively, and which also includes a stationary distributor block surrounding said rotor and having sparkplug .terminals in circular arrangement comprising two sets thereof cooperative with the electrodes at said periods of ignition; said electrodes being adapted to engage said terminals so that in each rotation of the shaft each electrode first cooperates selectively with terminals of one set equal in number to half thereof and then with terminals of another set equal in number to half thereof.

6. In multicylinder ignition generators of the multicoil gearless type; a shaft adapted to be driven by an internal combustion engine at the cam shaft speed thereof; a plurality of generating coils associated with the generator; circuit breaker mechanism electrically connected to the coils and having an element fast with the shaft; and distributor mechanism which includes a rotor fast with the shaft and having in one plane a like plurality of conducting segments angularly offset and insulated from each other and rotatable upon rotation of said rotor with the segments being electrically connected to the respective coils at the periods of ignition of the generator, and also having a like plurality of distributing electrodes angularly offset from each other in different planes and electrically connected to the segments respectively, and which also includes a stationary distributor block surrounding said rotor and having sparkplug terminals arranged in two circles cooperative selectively with respective electrodes at said periods of ignition.

7. In multicylinder ignition generators of the double gearless type; a shaft adapted to be driven by an internal combustion engine at the cam shaft speed thereof; two generating coils associated with the generator; circuit breaker mechanism electrically connected to the coils and having an element fast with the shaft; and distributor mechanism which includes a rotor fast with the shaft and having in one plane two ring conducting segments extending around a substantial portion of said rotor and angularly offset and insulated from each other and rotatable upon rotation of said rotor with the segments arranged to be electrically connected to the respective coils at the periods of ignition of the generator and also having two distributing elec trodes angularly offset from each other and in different planes and electrically connected to respective segments, and which also includes a stationary distributor block surrounding said rotor and having two sets of sparkplug terminals cooperative selectively with electrodes at said periods of ignition.

8.,In multicylinder high tension ignition generators of the multicoil gearless type; a shaft adapted to be driven by an intenial combustion engine. at the cam shaft speed thereof; a plurality of high tension generating coils associated with the generator and having primary and secondary windings; circuit breaker mechanism electrically connected to the primary windings of the coils and having an element fast with the shaft; and distributor mechanism which includes a rotor fast with the shaft and having in one plane a like plurality of ring conducting segments extending around a substantial portion of said rotor and rotatable upon rotation of said rotor and angularly offset and insulated from each other with the segments arranged to be electrically connected to the high tension windings of respective coils at the periods of ignition of the generator and also having a like plurality of distributing electrodes angularly offset from each other and in different planes and electrically connected to respective segments, and which also includes a stationary distributor block surrounding said rotor and having sparkplug terminals cooperative selectively with electrodes at said periods of ignition.

9. In multicylinder high tension ignition generators of the multicoil gearless type; a shaft adapted to be driven by an internal combustion engine at the cam shaft speed thereof; a plurality of high tension generating coils associated with the generator and having primary and secondary windings; circuit breaker mechanism electrically connected to the primary windings of the coils and having an element fast with the shaft; distributor mechanism which includes a rotor fast with the shaft and having in one plane a like plurality of ring conducting segments extending around a substantial portion of said rotor and angularly offset and insulated from each other and rotatable upon rotation of said rotor and also having a like plurality of distributing electrodes angularly offset from each other and in different planes and electrically connected to respective segments, and which also includes a stationary distributor block surrounding said rotor and having sparkplug terminals cooperative selectively with electrodes at the periods of ignition of the generator; and high tension connectors fastened to respective terminals of the secondary windings of said coils and in jump spark connection with respective segments at said periods of ignition. I

10. In a multicylinder magneto of the double gearless type; a shaft adapted to lie-driven by an internal combustion engine at the 'cam shaft speed thereof; generator mechanism including a magnetic rotor fast with the shaft and a magnetic stator cooperative with the rotor and including two generating coils; circuit breaker mechanism electrically connected to the coils 1 includes a stationary distributor block surrounding said rotor and having sparkplug terminals cooperative selectively with electrodes at the periods of ignitionof the magneto; and conductors electrically connecting the coils to the segments at said periods of ignition.

11. In a high tension multicylinder magneto oi the double gearless type; a shaft adapted to be driven by an internal combustion engine at the cam shaft speed thereof; generator mechanism including a magnetic rotor fast with the shaft and a magnetic stator cooperative with the rotor and including two high tension generating coils with primary and secondary windings; circuit breaker mechanism electrically connected to the primary windings and having an element fast with the shaft; distributor mechanism which includes a rotor fast with the shaft and having in one plane two ring conducting segments extending around a substantial portion of said rotor and iangularly offset and insulated from each other and rotatable upon rotation of said rotor and also having two distributing electrodes angularly offset from each other and in different planes and electrically connected to respective segments, and which also includes a stationary distributor block surrounding said rotor and having sparkplug terminals cooperative selectively with the electrodes at the periods of ignition of 10 the magneto; and conductors electrically connected to the terminals of the secondary windings of the respective coils, and in electrical connection with respective segments at said periods of ignition.

12. In a high tension multicylinder magneto of the double gearless type; a shaft adapted to be driven by an internal combustion engine at the cam shaft speed thereof; generator mechanism including a magnetic rotor fast with the shaft and a magnetic stator cooperative with the rotor and including two high tension generating coils with primary and secondary windings; circuit breaker mechanism electrically connected to the primary windings and having an element fast with the shaft; distributor mechanism which includes a rotor fast with the shaft and having in one plane two ring conducting segments extending around a substantial portion of said rotor and angularly offset and insulated from each other and rotatable upon rotation of said rotor and also having two distributing electrodes angularly offset from each other and in different planes and electrically connected to respective segments, and which also includes a stationary distributor block surrounding said rotor and having sparkplug terminals in jump spark connection with the electrodes selectively at the periods of ignition of the magneto; and conductors fastened to the terminals of the secondary windings of the respective coils and in jump spark connection with respective segments at said period of ignition.

WOLFGANG E. SCHWARZMANN. EDWARD M. BACH.

REFERENCES CITED The following references are of record in the file of this patent: 

